JSFiddle - React, Tailwind, and code Playground

HTML

<table  border="1">
    <col id="col0" style="background-color: #FFFF00"/>
    <col id="col1" style="background-color: #FF0000"/>
    <tr><td rowspan="2">1</td><td>2</td><td>3</td></tr>
    <tr><td>4</td><td>5</td><td>6</td></tr>
    <tr><td>7</td><td>8</td><td>9</td></tr>
</table>

CSS

td{width:50px;}

JavaScript

$('table td').click(function() {
    var cell = this;
    var i_col = 0;
    var tr = $(this).parent('tr');
    var table = tr.parent();

    tr.children().each(function() {
        if ($(this)[0] == cell) {
            alert('collumn found: ' + i_col);
        }
        i_col++;
    });
});